Conventionally, for example as described in JP 2005-30327 A, dimethyl ether (DME), which is a type of liquefied gas fuel, is accumulated in a common rail after an internal engine is stopped. The DME is heated by the internal combustion engine, and as a result becomes a high pressure gas. In this case, the DME may leak into the combustion chamber. After leaking into the combustion chamber, the DME may cause abnormal combustions to occur when the internal combustion engine is started.
In this regard, according to the fuel supply device of JP 2005-30327 A, a purge tank is used to temporarily collect the DME remaining in the common rail. The purge tank is at a lower pressure than the fuel tank. Then, the vaporized DME in the purge tank is re-liquefied by a compressor and transferred to the fuel tank. Due to this operation, the DME in the common rail is collected into the fuel tank.